Earth scraper



June 9, 1936.

P. C. ANDERSON EARTH SCRAPER Filed Dec. 24, 1954 PAUL 0 6. A/MQHPSOA/ Patented June 9, 1936 iIlTED STATES PATENT OFFICE 3 Claims.

This invention relates to an earth scraper of the type commonly known as a Fresno, that is, a scraper adapted to be drawn over the ground so as to scrape up a load of earth, rock or other material, and provided with a handle or Johnson bar by means of which the forward edge may be brought into engagement with the ground so that the pulling force will invert the scraper to dump the contents thereof. When in the inverted position, the scraper rides upon forwardly extending runners which support it out of engagement with the ground.

The principal object of this invention is to provide highly eihcient and long wearing protecting shoes for these runners so as to prevent wear and damage thereto.

Another object of the invention is to so construct the protecting shoes that they can be easily attached or detached and, when in place, will be rigidly and firmly locked to the runners against both lateral and longitudinal displacement.

A further object is to so construct the shoes that they will be adaptable to all runners regardless of the spacing of the bolt holes therein, so that they will firmly hold the bolts while the nuts are being tightened or removed and so that they will allow the bolts to be easily removed should it be desired to replace or renew the shoes.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

Fig. 1 is a perspective View illustrating a typical scraper of the Fresno type with the invention applied thereto.

Fig. 2 is a plan view of the upper extremity of one of the protecting shoes.

Fig. 3 is a cross section through the shoe and runner taken on the line 3-ii, Fig. 2.

Fig. 4 is a cross section through an alternate type of shoe.

The drawing illustrates at 10 a typical Fresno scraper with its Johnson bar at H, runners at l2, and draw bar at I3. The runners are each provided with two bolt holes for the attachment of shoes and their forward extremities are curved.

to provide arcuate running surfaces when the scraper i0 is in the inverted or discharging position. In use these surfaces rapidly wear away from the constant friction with the earth, sand, gravel, etc.

Attempts have been made to place shoes upon these surfaces, but these attempts have not been practical. The bolt holes are not spaced uniformly since the distortion in bending the runner and differences in manufacture etc., places the bolt holes at varying positions. Therefore the usual shoes must be drilled to fit the particular runner upon which they are to be placed, thus involving delays, expense and inconvenient field work. In the usual shoes, the bolts must be well counter-sunk or their heads will be quickly worn away. These counter-sunk bolts become loosened and their nuts rusted in place, and it is impossible to remove the bolts or tighten the nuts since the bolt heads will revolve in the round, countersunk holes. Therefore to replace an ordinary shoe or even tighten the bolts thereof, it is necessary to cut the bolts from place and replace them with new ones, causing considerable delay in use. The usual shoes also frequently work to one side or another, putting the scraper temporarily out of service.

This invention is designed to eliminate all of the above troubles and provide a shoe which will be held positively and permanently and yet with which the bolts can be easily and quickly tightened or removed and in which any spacing of bolt holes which may be found in a runner can be accommodated with a single standard shoe.

The improved shoe is illustrated at M and is curved to fit the average curve of the runners l2. The back of the shoe is inset to receive the runner so that two holding flanges I 5 are formed along the inner edges which firmly engage the sides of the runner l2 and prevent the shoe from slipping laterally from place thereon. The shoe is preferably formed of a wear' resisting cast metal, which will outlast many ordinary sheet metal or structural metal shoes. The flanges 15, in addition to providing means for holding the shoe in place, greatly increase the structural strength thereof and provide sufficient strength even though the runner surface may be well worn down as the flanges themselves can never be subjected to wear.

Each extremity of the shoe is tapered to a relatively sharp edge as shown at I9 so as to provide a smooth continuous rocking or rolling surface. The mid-portion of the shoe which is subjected to the greatest wear is relatively thicker than the end portions thereof. The extremities are formed with inwardly extending bolt slots IS. The slots Iii are sufiiciently long to accommodate the minimum bolt hole spacing to be found in scraper runners. The outer edges of the upper slot 16 are formed with a series of triangular depressions or notches I! for engaging the corners of a square head bolt such as indicated at l8.

This construction serves a triple purpose, first it prevents the bolt from turning while the nuts are being tightened or loosened; second, it prevents the shoe from shifting vertically or longitudinally on the runner since the engagement of the bolt head in the triangular depressions prevents any longitudinal shifting of the shoe; and third, it allows a standard shoe to be fitted onto any runner regardless of the bolt hole spacing.

It is preferred to employ the triangular notches l! in the upper slot I6 only so that the shoe can be shifted at the lower slot to accommodate any fractional spacing of the bolts between the notches I 7. However, if it is desired, the triangular notches may also be provided at the bottom slot E6.

The shoe [4 may be formed with a wider tread than the usual runner I2 for use in soft earth, etc. This gives a greater wearing surface, as well as preventing the shoe from swinging into the ground. Such a shoe is indicated in cross section in Fig. 4, in which the socket for receiving the runner I2 is indicated at 20 and the wide bottom tread is indicated at 2 l.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent 1. A wearing shoe for Fresno scrapers comprising: an arcuate channel member having slots extending inwardly from each of its extremities for receiving bolts to attach said member to said runner; and a series of triangular, oppositelyplaced notches along the edge of one of said slots for engaging the corners of a bolt head.

2. A protecting shoe for the curved portions of the runners of a Fresno scraper comprising: a curved cast shoe of greater thickness at its middle than at its extremities and having a channel formed in its rear or concave surface for receiving a runner; and inwardly extending longitudinal slots along the center line of the wearing surface and at each extremity of said shoe for receiving bolts to attach said shoe to said runner.

3. A protecting shoe for the curved portions of the runners of a Fresno scraper comprising: a curved cast shoe having a channel formed in its rear or concave surface for receiving a runner; inwardly extending longitudinal slots at each extremity of said shoe for receiving bolts to attach said shoe to said runner; and a series of countersunk depressions or notches along the opposite edges of one of said slots for receiving the head of a bolt.

PHILIP C. ANDERSON. 

